Self-lubricating and internal-pressure spring



March 8,1927. 1,620,301

. c. THIDE SELF LUBRICATING AND INTERNAL PRESSURE SPRING Filed May 11, 1925 o o If v l7 mmvroa CHARLES 771/05.

A TTORNE Y.

ED S If Patented Mar. 8, 1927.

r ater es" ri-nnnyortenooxixlv; NEW roan.

SELF-LUBRICATI=NG Ann INTERNAL-PRESSURE SPRING.

Application filed May 11, 1925. Serial No; 29,525. T

Thisinventionj relates to novel and useful improvements 111 springs and more particularly to what Iterm aninternal pressure and self lubricating spring wherein aplurality of superimposed leaves, when connected, are provided with a lubricating chamber so that the lubricant may fiowhbetweenthe respective leaves duringthe vary or grooved, it is weakened at some point or i andnt the same timeprovid'e for a lubricatmg stresses and strainscplacedon the spring.

I It has beenthe aim andobjeot of springdesigners to construct leaf springs for motor vehicles and thel'ilc'etoirelieve and eliminate asifar as possible that quality in the metal known as fatigue. Various means have been resorted to in slotting or gro'ovingthe individual leaves and providing communicating passages therebetween so that the lubricant may flow between the crevicesofsaid leaves; I amaw'are of, the existence of that.

class of springs whereinthe individual leaves are slotted, at different points on each "side 'of'the central co'nneotingbolt and to others which provide a central groove and communicating passages for the flow of oil or the lubricant. Whenever, alspring iswslotted points betweenits ends. 'lhe natural result is .th at theslntmgand particularly the superimposed leaves are fractured or broken because the stresses and strains imposedon the 7 leaves is not equally distributedthroughout their areas andconsequentlythe leaves are subject to a fracture at; its weakest point.

It is my object .andyaim to provide a self lubricatingspring constructed of"superim-.

posedleaves wherein each of the leaves shall be of uniform strength throughout its area ingbchamber on .each side of the central connecting bolt so that the lubricant may 'liowbetween the crevices-0f theleaves 1n,

properproportion to the movement of the connected leaves. a a

In'order to more fully understand andap- 'preciate my invention,referencefis had tothe a preferred accompanying drawing, showing embodiment thereof, wherein, 1 r Figure 1 is a side View. Figure 2 is a longitudinal sectional view. Figure 3 is a sectional View taken on the line33 of Figure 2..

Figure 4 is a plan of one of the internal leaves.

Figure 5 is a sectional view showing the superimposed leaves and the lubrlcatmg chamber.

Figure-6 is a'sectional end view, taken sub-i stantially on thefline 6.6 of Figure 5.

Referring now, to the drawings wherein like reference characters designate corresponding; parts throughout all the views, 5 designates the top main leaf which is'bent or ar'ched throughout its length and termi-. nates-in the eyes 6,, 7, whereby the spring I may -be.atta'ched to theichassis of an auto- 1'nob1le,1for instance- There are provided a pluralityof superimposed leaves 8, connected by the straps 9, 10, and a central connecting? bolt 11, said leavesbe-ing of the same width but decreasing in length from the main top leaff). to: the shortest bottom leaf 13; a

dilach leaf 8 is provided with a central,

longitudinal'groove,14, out through the material of ,theTle-af'sothat when saidsuperimposed leavesarewjoinedby the straps 9,

,10, a lubricating chamber l o is thus, formed 7 and provided being located onopposite sides of the central connecting bolt. 11. The chambers are adapted to receive the-lubricant either through such devices as'alemite cups 16 or tl'irough other? suitable lubricating,

feeding devices whereby said chambers may function as a compression"chamberor a replenisl'iing chamber avheh varying stresses" and strains are exerted. onthe'sprinm lt is-well known in spring construction that when the, superimposed V leaves are slotted, they are'necessarily. weakened. The

objection heretoforeexperienced in providmgslots or groovesat ClIffGIQDUPQlIltS in a leaf spring has been, that; a fracture :or

break occurs ata weakened point and; this is due to the fact that the spring and the superimposed leaves are not of uniform' strength throughout their area. My aim: and object therefore is to construct aspring a-nd'particularlythe leaves so that the pres-- sureper square'inch exerted .on each of the" leaveslwilllbe uniform as opposed to being. s aronger at one point than at another bv. reasoniof the slots above referred .to'. In Figures 4 and 5, it will be observed that the-longitudinal: slots. l lvin each .of the leaves 8 is cut so as to provide a central thickenedportion 17 of the material of the leaf at a point through which the central bolt 11 passes; This is necessary since the leaf is weakened by reason of providing the aligned apertures for the passage of the connecting bolt. The slot'l l does not terminate abruptly but on the other hand, its

bottom wall slants upwardly toward the ends 19. On each side of the slot 14 and at points located adjacent the .ends of the leaves I provide What I term compensating slots 20, 21, the purpose of which ,to Weaken the leaf at this point so that its strength will be uniform.

In order to permit a certain quantity of the lubricant to pass from one chamber 15 to the other and in and about the connecti-ng bolt .11, each of the superimposed leaves arenotched as at 22, said notches varying in their :taperlfrom the bottom "leaf to the topzleaf as the pressure per square inchon the leaves increasesdue to the length of said sleaves, which aids the penetrating power of the lubricant as pressure becomes greater. The spring thus formed possesses the neqnired flexibility and resiliency with the additional advantage that the lubricant may ipass betiveen the crevicesof the superimposed -'lea:ves and maintain the spring in proper condition. The stresses and strains incident to the spring aretaken up and com pens-ated for and since the construction possesses uniformstrength throughout its area, itsfraetureisitlnis avoided. It willof course be recognized that the width or length of the leavesof the springas Well as the required thicknessof themetal may be varied as'cireumstances andoccasions may require, it be-' ing recognized that :thespringmust be built in proportion to the load which it isito carry. \Vhile 1 have illustrated and described my invention with some degree of particularity, I irea'lize that in practice various alterations :therein may be made. I therefore a eserve the right and privilege of changing the form of the detailsrof construction or otherwise altering the arrangement of :the correlated :parts Without departing from thespiritof theinvention or :the scope of the. appended claims.

, Having thus described my invention, What I .claim as new and desire to secure by United States Letters Patent is 1. A leaf spring comprising a. plurality of superimposed leaves having a central connecting element, eachiof said leaves, exceptthe :top leaf, being slotted longitudinally throughout its length forming a lubricating chamber on each side of the connecting element, the bottom walls of said slots slanting upwardly at the endsof the leaves, and compensating slots in the ends of said leaves.

-52. A leafspringcomprising. a plurality of superimposed leaves having a central connecting element, each of said leaves being slotted continuously throughout its length forming a lubricating chamber on each side of the connecting element, said leaves being notched adjacent the-connecting element for the passage of lubricant from one chamber to .the other.

3. A leaf spring comprising a plurality of superimposed leaves having a central connecting element, each of said leaves, except the top leaf, being slotted longitudinally, said slots having upwardly slanting Walls at the ends of the leaves and at the centers thereof whereby the said leaves are thielo ened, a lubricating chamber formed by said slottethconneeted leaves on each side of the connecting element, said chambers being .in communication for the passage of the lubricant from one chamber :to the other.

i. A leaf spring comprisinga plurality of superimposed leaves having a centralconnetting element, each of said leaves, except the top leaf, being slotted longitudinally throughout its length, the bottom walls of said slots slanting upwardly at the ends and at the centers of th .leaves thereby providing thickened portions of the material of said leaves, compensatin slots on each side of the groove adjacent the ends thereof for equalizing the strength of the leaf, said connectedleaves forming a lubricating chamber on each side of the central connecting. element, said leaves being notched adjacent said element permitting the flow of lubricant from one chamber to the other.

A leaf springcomprising a .pluralityof superimposed leaves having a central connecting holt, each of said leaves, except the top leaf, being continuously slotted longidi-nally throughout its length forming a lubricatingchamber on each-side of the connecting bolt, the bottom Wallsof said slots slanting upwardly at the ends and at the centers of said leaves thereby providing thickened portions of the material of the leaves, compensating slots attheends of the leaves equalizing the strength thereof, said leaves having notches of varyingdegrees from the bottom to the leaf adjacent 'the;top leaf for the passage of :lubricant from one chamber to the other in and about the central connecting bolt.

In testimony whereof I affix my signature.

CHARLES THIDE. [L. a] 

